JPS58203385A - Electric furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric furnace having a liquid cooling device for a wall portion of the furnace body subjected to a high heat load, the cooling pipes being arranged substantially vertically and through which liquid flows. are connected in series for each group, and pi-ξ ports are provided between adjacent cooling pipe passages in the upper part of the furnace body.
It particularly relates to arc furnaces of the type in which the ports at least partially short-circuit the cooling tube passages.

This type of furnace is described in Swiss patent application No. 3280/81-4.
In this case, air bubbles that occur due to local overheating can be eliminated, which not only has an adverse effect on the cooling effect but can even damage the cooling device. As a solution for easy removal from the cooling system, it is specifically disclosed to arrange . . .

Publication date unknown” Korf-Fuchs-8
systemtechnjk: Stablerzeu
gung: Wasserkffihlsystem
A cooling box is known based on "fiir L]chtbogenδfen", which cooling box
It is integrated into the furnace body of the arc furnace either individually to form the furnace wall or as a complete cooling system. In this case, it is necessary to take measures to prevent cooling water from entering the furnace chamber in the event that the cooling box is damaged. A protective layer made of refractory material is attached to the wall surface of the cooling box near the core, which is relatively thin compared to the thickness of the wall of the refractory material furnace body that is not conventionally cooled in an arc furnace. from radiant heat while preventing excessive heat extraction from the melting chamber. During melting, this protective layer is additionally thickened by slag spatter, which bounces off and remains attached to the furnace walls under the influence of the arc. The protrusions provided on the walls of the cooling box strengthen the adhesion between the refractory material and the slag spatter.

Also in 1980 Ushizuki Lactromelt Corpo
Publication “Water Coole” published by ration
Similar water-cooling systems for the walls of arc furnaces are known based on ``D Panels''.

If a cooling box is used to cool the furnace wall of an arc furnace, the refractory material is cut out, but on the other hand, if the protective layer applied to the cooling box wall is relatively thin, the protective layer The layer may be formed in certain places by, for example, mechanical action during the charging operation, or by the action of steel baths or slag sputtering during the melting process, or by inhomogeneous radiant heat, indeterminate cooling action, or There is a risk of peeling off due to thermal stress inside the protective layer due to cooling of the furnace wall during operation. Heat transfer and therefore heat loss is particularly pronounced at exposed areas where the metal surfaces of the cooling box are directly exposed to arc irradiation.

In addition, the well-protected cooling zone wall area is subject to a stronger thermal load than other protected areas, and when continuous melting is performed in two or three shifts in steel plants and foundries, the furnace operation Areas of high fever may occur that go unnoticed by personnel. In the worst case, where this high-temperature part is exposed and insufficiently cooled, it will be damaged by overheating, and serious accompanying phenomena will occur as a result. Detection equipment for monitoring cooling systems is expensive. If an error is indicated, the furnace must be shut down in order to repair the damaged area.

In addition, the cooling wall of the cooling box near the core expands and expands due to strong temperature fluctuations, despite being covered with a protective layer.
Constantly subjected to contractile force. This stress is particularly noticeable at the corners and ridges of the cooling surfaces, and thermal stress occurs at the welded joints that join the cooling surfaces, which may crack in some cases and cause the cooling water to This will cause an eruption of water.

The problem of the present invention, which uses the above-mentioned prior art as a starting point, is to
In particular, the cooling system for arc furnaces has been improved to simplify the structure, make it more economical to manufacture, increase the service life of the furnace wall, and improve the safety of the cooling system so that damage cases can be almost completely eliminated. It is to provide sex.

The gist of the present invention to solve this problem is that the cooling pipes are arranged in a two-layer array, and the cooling pipes outside the layer near the core are integrated and are curved in a U-shaped arc at the lower and upper ends. Cooling pipes outside the layer near the outer periphery of the furnace body are connected to the upper and lower ends of the furnace body, and openings are made to cooling liquid distribution passages provided with internal ports. The cooling pipe outside the layer near the core is sunk into the refractory material and forms a reinforcing material for the refractory material.

The advantages of the invention are as follows.

(a) By configuring the cooling pipe as one piece and rounding the upper and lower ends, heat is uniformly absorbed or released by the cooling pipe. Edges and corners and material joints are avoided in the core cooling pipe section, so thermal stresses are not formed in this cooling pipe section, and the cooling system is sufficiently isolated from the effects of temperature alternating stresses. It's dripping.

(b) Cooling of the high-grade refractory material reduces the wear of the refractory material, thereby increasing the useful life of the furnace wall.

(c) Based on the fact that the coolant distribution passage or the distribution chamber includes the . It is mixed with a cooling liquid, which prevents overheating.

According to the embodiment set forth in claim 2, the mutual spacing between adjacent cooling pipes outside the core-side layer is 1.0 mm of the outer diameter of the cooling pipes. ,,,(P is almost twice as large. As a result,
Optimum cooling of the refractory material is ensured and sufficient strength is provided to the support structure of the refractory reservoir, while the weight of the cooling pipe/refractory composite is kept low.

In an embodiment as claimed in claim 3, the cooling pipes as well as the refractory material are installed in the furnace body as segmented wall elements manufactured in a predecessor factory (prefabricated). This allows efficient assembly and disassembly of the segment wall elements and minimizes furnace downtime.

In the embodiment according to claim 1, each wall element has its own cooling circuit. The advantage of this embodiment is that the cooling effect is stronger both for the furnace body as a whole and for each wall element.

In an embodiment as claimed in claim 5, the flow ports in the coolant distribution channels are larger than the amount of coolant flowing through the cooling channel, taking into account the fluid resistance of the associated cooling channel. A small presettable amount of coolant is designed to flow through the ports.

In the embodiment according to claim 6, the no.ζ and ξ ports in the cooling liquid distribution passages are arranged such that the amount of cooling liquid flowing through the cooling pipes is determined by taking into account the fluid resistance of the cooling pipe passages to which they belong. A presettable amount of coolant equal to or greater than
It is designed to flow through ζi and ξsport.

Advantages of the embodiments according to claims 5 and 6 include the flow rate and flow rate of the coolant introduced into the cooling pipe passages, and also the fact that the cooling pipe passages themselves are designed such that: This means that if part of the coolant evaporates in the cooling pipe passages, the vapor immediately flows through the... It must be removed from the cooling system, and in that case no mutual influence between the cooling liquid and the steam that is detrimental to the cooling effect can occur. In this way, unlike conventional liquid cooling systems, a combined cooling system of liquid cooling and steam cooling is obtained, and the heat required for evaporation is extracted from the structural member to be cooled, thus providing cooling. That is why it is used. The flow rate of the coolant in the cooling tube is designed such that vapor bubbles do not stick in the upper arc of the cooling tube, but are rather carried away by the coolant and carried into the coolant distribution passage.

Next, embodiments of the present invention will be explained in detail with reference to the drawings.

A furnace body 1 of an arc furnace equipped with a furnace lid 5 is a platform 6
the platform is supported within an opening of the
The two swing bridges are supported on a platform 7, the platform itself being fixedly anchored to the foundation 9, and the bridge supported on a platform beam δ. In FIG. 1, reference numeral 2 indicates a hot water outlet. A movable rotating support 10 is arranged on the platform 6, and a furnace lid lift and rotation device 11 is attached to the rotating support.

The furnace lid lift and rotation device 11 consists of a support arm 13 and a column 12 for the support arm.

In addition, the platform 6 has three electrode adjustment columns 14.
However, only one of them is shown in Figure 1. Each electrode adjustment column 14 is hydraulically movably coupled to an electrode adjustment cylinder 15 in the vertical direction.

An electrode support arm 16 is fixed to the electrode adjustment column 14, and an electrode 18 is held in an electrode holder 17 at the outer end of the electrode support arm.

Only one of the total three electrode support arms 16 is shown, and as for the trench electrode 18, the third electrode is hidden, so that only two electrodes are visible in the drawing. . The furnace lid 5 includes a furnace lid ring 4 that rests on the furnace lid support ring 3 of the furnace body 1, and a flue gas discharge connecting pipe 19 having a flange 20 is arranged on the furnace lid 5. The fixing mechanism of the flue gas exhaust connecting pipe 19 is shown in FIG. It is only abbreviated.

Φ support rings 22 are attached to the furnace lid rig 4 of the furnace lid δ, and in the embodiment shown in FIG. 1, support ropes 23 are respectively fixed to each support ring.

A total of four support cables 23 are guided via pulleys 24 which are pivotally supported by a pulley support 25 provided on the support arm 13 . The support rope 23 is connected to a hydraulic cylinder 26 that raises and lowers the furnace lid 5 with respect to the furnace body 1 .

From FIG. 2 onwards, parts corresponding to those in FIG. 1 are given the same reference numerals.

FIG. 2 is a plan view of the arc furnace shown in FIG. 1, but with the furnace lid 5 removed. Reference numeral 27 denotes a prefabricated wall element, which is arranged inside the outer peripheral wall of the furnace body l.

In the embodiment shown in FIG. 2, six wall elements 27 are installed, but the number of wall elements 27 varies depending on the size of the furnace. Moreover, the number of wall elements 27 advantageously increases as the size of the furnace increases. In FIG. 2, a furnace bottom 28 is shown inside the furnace body 1, and a slag door 29 is disposed opposite the tap 2. As shown in FIG.

The third section shows the furnace body 1 in cross section along the line ■-■ in Figure 2.
As can be seen from the figure, inside the wall element 27 there is a cooling system 3.
0, 31, 32, and the cooling system consists of a cooling tube layer array 30 closer to the core, a cooling tube layer array 31 closer to the outer periphery of the reactor body, and a coolant distribution passage 32. The connecting conduits required for the cooling system 30, 31, 32 outside the outer wall of the furnace body have been omitted in FIG. 3 for clarity.

The partial vertical sectional view of FIG. 4 shows the cooling system 30't31.
32 as well as refractory material 35 are shown.

As can be seen from FIG. 4, the cooling tube layer array 30 near the reactor core has a U-shaped arc portion at the upper and lower ends, and the ends of the arc portion are integrally formed with the cooling tube layer array 31 near the outer periphery of the reactor body. Connected. The ends of the cooling passages 31' of the outer cooling tube layer array 31 are connected by inlet ports 37 on the one hand and by outlet ports 38 on the other hand.
The cooling liquid distribution passage 32 is opened by the cooling liquid distribution passage 32 . Each wall element 27 is fixed to the outer peripheral wall of the furnace body 1 by a fixed joint plate 36 and consists of a cooling system 30, 31, 32 and a refractory material 35.

As can be seen from FIGS. 4 and 5, the coolant distribution passage 32
A pipe port 34 is provided between the upper closing plate 32' and each partition wall 33, respectively.

In FIG. 5, reference numeral 40 indicates a coolant inflow port, and arrow 39 indicates the flow direction of the coolant. According to FIG. 5, the coolant first flows downward through the rightmost cooling pipe 30 near the core, is diverted through the lower arc portion, and flows through the cooling passage 31' of the cooling pipe 31 near the outer periphery of the reactor body. and flows upwardly through the inlet port 37 and into the coolant distribution passage 32 . In the coolant distribution channel 32 the coolant flow is divided into two sub-streams as indicated by arrows 39. 1st
A partial flow of is passed through outlet port 38 to coolant distribution passage 32.
It flows out again from the cooling pipe 30, first flows upward in the direction of the arrow 39, is diverted through the upper arc, and flows into the cooling pipe 30 near the core.
□ Flows downward through the lower end arc portion □ and is diverted through the cooling passage 3 of the cooling pipe 31 near the outer periphery of the furnace body.
1' and flows upwardly again through the inlet port 37.
and into the coolant distribution passage 32 . Since the cooling pipes 3o are arranged close to the reactor core, the first partial flow of the coolant is heated and is not only in the coolant distribution passage 32 but also in the intermediate region between the two partition walls 33 shown in FIG. , merges with a second partial flow which has been deflected in the horizontal direction and has flowed through the . The second sub-stream of the cooling liquid is
The first partial stream of coolant is cooled by the second partial stream since it has a relatively lower temperature level than the first partial stream flowing through the near-core cooling pipes 30 . The coolant portion heated by flowing through the core-side cooling pipe 30 and the coolant distribution passage 32
The operation process of cooling by the portion of the cooling fluid that remains in the furnace body 1 and flows through the o-sport 34 is performed by cooling the cooling tube layer arrays 30 . 31.

In order to prevent vapor bubbles from forming inside the cooling pipe 30,
.

If this occurs, steam and air bubbles will collect at the upper arc, obstructing or interrupting the coolant circulation. In order to avoid such an inconvenient situation, the flow rate of the cooling liquid is adjusted to the cooling pipe 3.
In the event that a vapor bubble should form in the upper arcuate portion of the 0, the vapor bubble is selected to be carried by the cooling liquid into the cooling liquid distribution passage.

In FIG. 5 only one embodiment of the idea of the invention is illustrated. The invention can also be implemented in such a manner that the coolant distribution passages are arranged obliquely to the horizontal and at an angle opening in the direction of flow of the coolant. In this manner, vapor bubbles are removed from the coolant distribution passages 32 more quickly. The arcuate portions at the upper and lower ends of the cooling pipes 30, 31 are necessary for the reason of homogenizing the heat load and are an absolutely essential requirement.

FIG. 6 is a horizontal sectional view of the cooling system 30, 31, 32 and refractory material 35 shown in FIG. 5, and as can be seen from this FIG.
and 31 are arranged sideways in the horizontal direction, and are arranged in a so-called spiral shape in the circumferential direction.

In the cross-sectional view of FIG. 6, the configuration in which the cooling pipes 3o and 31 are horizontally shifted laterally is only schematically shown by the lower arcuate portion indicated by a broken line.

Furthermore, from FIGS. 4 and 6, it is clear that the cooling pipes 30 and 31 form a double-layer array, and that the cooling pipes 3, which are subject to a strong heat load,
It can be seen that 0 is not connected, for example by a welded joint.

Furthermore, in the cooling pipe 30 and at the transition point from the cooling pipe 30 to the cooling pipe 31, any edges and corners are excluded in order to reduce the thermal load on the cooling system 30, 31, 32.

[Brief explanation of the drawing]

Fig. 1 is a schematic front view of one embodiment of the arc furnace, Fig. 2 is a schematic plan view of the furnace body of Fig. 1 with the furnace lid removed;
Figure 3 is a cross-sectional view of the furnace body along the line Ijl-m in Figure 2;
Figure 4 is a partially enlarged vertical sectional view of the configuration of the cooling pipe and refractory material shown in Figure 3, Figure 5 is a vertical sectional view taken along line ■-V in Figure 4, and Figure 6 is a vertical sectional view of the cooling pipe shown in Figure 3. It is a horizontal cross-sectional view along the VI-VI line of a figure. ■... Furnace body, 2... Hot water outlet, 3... Furnace lid support ring, 4... Furnace lid ring, 6... Zolat Foem,
7...The swing receiver is a stand, 8...The receiver is a stand beam, 9...
Foundation, 10...Rotating support, 11... Furnace lid lift and rotation device, 12... Column for support arm, 13... Support arm, 14... Column for electrode adjustment, 15... Electrode Adjustment cylinder, 16... Electrode support arm, 17...
Electrode holder, 18... Electrode, 19... Flue gas discharge connection pipe, 2o... Flange, 21... Guide rail, 22... Support ring, 23... Support cable, 24...・
Pulley, 25... Pulley support, 26... Hydraulic cylinder, 27... Wall element, 28... Furnace body bottom, 29...
...Slag door, 30...Cooling pipe layer row near the core, 3
1... Cooling pipe layer array near the outer periphery of the furnace body, 32... Coolant distribution passage, 30', 31 (... Cooling passage, 32'...
- Upper closing plate, 33... Partition wall, 34... Pi/ξ sport, 35... Fireproof material, 36... Fixed joint plate, 37... Inlet port, 38... Outlet port, 3
9...Direction of flow of coolant, 40...Engraving of the drawing of the coolant inlet port (no change in content) Figure 2 Procedural amendment (method) July 1, 1980, Case 1 of the Commissioner of the Patent Office Indication of 1982 Patent Application No. 11605 2,
Name of the invention: Electric furnace 3. Patent related to the person making the amendment: Name of the patent applicant: P.P.R.N.I. Akchengesellschaft Braun Severi Land Konnohii.4, Agent: February 26, 1982 (Shipped) (Japanese) 6. Drawings subject to correction 7. Contents of correction

Claims (1)

[Claims] 1. An electric furnace having a liquid cooling device for a wall portion of the furnace body subjected to a high heat load, in which cooling pipes arranged substantially vertically and through which liquid flows are arranged in groups. In addition, there is a connection between adjacent cooling pipe passages in the upper part of the furnace body.
In the case where the cooling pipes (30, 31) are arranged in a two-layer row, the cooling pipes (30, 31) are arranged in a two-layer row. The cooling pipes (3o) in the layer row near the core are integral and curved in a U-shaped arc shape at the lower and upper ends, and the cooling pipes (31) in the layer row near the outer periphery of the reactor body are arranged at the upper and lower ends. is connected to and opens into a coolant distribution passageway (32) having pi/xi ports (34) provided therein, and at least the cooling pipes (30) of the layer near the core are made of refractory material (35). )
An electric furnace, characterized in that the electric furnace is embedded therein and forms a reinforcement of the refractory material. 2. The electric furnace according to claim 1, wherein the distance between adjacent cooling pipes (30) in the core-side layer array is approximately twice the outer diameter of the cooling pipes. 3. The cooling pipes (30, 31) and the refractory material (35) are
Segment-shaped wall elm (previously manufactured) (27)
The electric furnace according to claim 2, which is attached to a furnace body as a furnace body. 4. The electric furnace according to claim 3, wherein each wall wall (27) has its own cooling circuit. 5. ・×・ξ ports in the coolant distribution passage (32) (
34) is the cooling passage (3) of the cooling pipe (30, 31) to which it belongs.
Taking into account the fluid resistance of
5. An electric furnace according to any one of claims 1 to 4, which is designed to flow through the electric furnace. 6. ···ξ·ξ spor in the coolant distribution passage (32)) (
34) is the cooling passage (3) of the cooling pipe (30, 31) to which it belongs.
0', 31'), a presettable amount of cooling liquid is equal to or greater than the amount of cooling liquid flowing through the cooling pipes (30, 31). An electric furnace according to any one of claims 1 to 4, which is designed to flow through a ξ sport (34).